In my U.S. Pat. Nos. 4,110,592, 4,563,563, 4,729,553, and 5,062,566, the disclosures of which are incorporated herein by reference, I have described methods and apparatus for the solder joining of copper and copper alloy tapes and carrier strips wherein the fusion of the solder occurs between carbon electrodes. In the application of my inventions to carrier strips for fine electrical connectors it has become increasingly important to make sure that none of the solder, which is supplied in the form of a fine tape or wire, should foul passage of the strips through subsequent operations. To this end I had been retracting the supply of solder as soon as possible after fusion. Now, however, I have discovered that my methods can be improved by automatically applying tension to the solder as it is supplied, so that excess solder is withdrawn as soon as it is sufficiently weakened by heating, although it is not actually fluidized, and I have devised novel means for practicing this method.